Urinary incontinence in dogs

Written by Dr Mirjam van der Wel, Principal Veterinarian at Vets Incorporated, Westering

Urinary incontinence is a condition where the dog loses control of its bladder.

The urine leakage usually happens when the dog is relaxed/sleeping, but it can also dribble out of the dog while it’s walking. In most cases, an incontinent dog still maintains the ability to urinate normally/consciously.

Note that the dog is often not aware of what’s happening as they don’t feel the “urge” to urinate.

So if you see your dog squatting to urinate (a conscious action), even if the urination is inappropriate or frequent, this isn’t the same as incontinence.

So what causes incontinence in dogs?

Incontinence can be broadly separated into bladder and urethral dysfunctions (the urethra is the tube that takes urine from the bladder).

• Urinary tract/bladder infections (cystitis) and bladder stones/crystals are the most common reasons for the bladder to become inflamed and this can lead to incontinence.

• Anatomical anomalies can bypass the urethral sphincter mechanism. The most common anomaly is ectopic ureters. This is a congenital disorder (something the dog is born with, a bit like a “manufacturing mistake”) where the ureters (the tubes from the kidney to the bladder) don’t empty into the bladder like they should but bypass the urethral sphincter mechanism, causing incontinence.

• Urethral dysfunction (inadequate closure pressure) includes urethral sphincter mechanism incompetence (USMI) in (spayed) female dogs, intervertebral disc disease, degenerative myelopathy and other neurological/spinal disorders.

• Finally, there are a number of diseases which increase the normal urine production. The urinary system is overwhelmed, with resulting incontinence. Common diseases that lead to an increase in water consumption (and thus an increase in urine production) are kidney disease, diabetes and Cushing’s disease.

• Some medications lead to an increase in drinking (with possible incontinence as a result). One of the most common medications responsible for this is prednisone, a frequently used medication in veterinary medicine.

How is urinary incontinence diagnosed?

Your vet will need a detailed history of your dog to establish if the symptoms are really incontinence or if something else is going on.

Signs of incontinence:

• Urine leakage or dribbling urine (the dog is unaware)

• Urine leakage when the dog is lying down or at night during sleep

• Urine scalding around the vulva or prepuce

• Excessive licking of the vulva or prepuce

As already mentioned, bladder stones or cystitis and a number of conditions (e.g. diabetes and kidney disease) can cause incontinence through inflammation or increased urine production, so your vet may perform a number of tests to rule those out.

An incontinence work-up generally includes a history/physical exam of the patient, followed by urine analysis, blood tests and abdominal ultrasound/x-rays, as necessary.

Your dog’s history may point in the direction of ectopic ureters: these are generally young dogs that have had the incontinence problem from an early age (the anatomical problem was present at birth).

A thorough history will also bring up behavioural or pain-related causes for inappropriate urination.

Incontinence treatment

Once underlying diseases and conditions have been ruled out or managed, your dog will be treated for incontinence.

Ectopic ureters will usually require surgery or laser-guided cystoscopic ablation. Many vets will refer these cases to a specialist surgeon. Unlike a number of common surgeries such as spaying or removing bladder stones, ectopic ureters are not a routine surgical procedure. In some cases, the problem can be managed with medication. Fortunately, ectopic ureters are an uncommon finding.

This leaves us with urethral sphincter mechanism incompetence (USMI). This is incontinence in spayed female dogs, with larger dogs being affected more frequently than smaller dogs. The reason for this variation is unclear and likely multifactorial. When dogs are spayed, their uterus and ovaries are removed. Removal of the ovaries leads to a reduction of the oestrogen hormone in the female. There are oestrogen receptors on the urethral sphincter, so less oestrogen can lead to a reduced sphincter function (resulting in incontinence). Some types of incontinence medication act as oestrogen replacement and thereby improve the sphincter function. Other drugs act directly on the smooth muscle receptors in the urethra to increase urethral tone and closure pressure. Your vet will discuss the pros and cons of the various options and work out what’s suitable for your dog. This type of incontinence is a fairly common disorder and medical management is generally successful.

And finally:

Sometimes, despite our best efforts, there may not be a complete resolution of urinary incontinence.

Here are some things you can do to make it easier for you and your friend:

• Use puppy-pads beneath their bedding. Good absorption and easier clean-up

• Prevent urine scalding by carefully keeping their prepuce and vulva clean

• Frequently encourage the dog to go outside to urinate

• Doggie-diapers can be especially helpful in older pets with incontinence caused by neurological disorders